It is known that line-switching telecommunication systems can be replaced through packet-switching telecommunication systems, functioning, for example, on the basis of IP (IP: Internet Protocol). Such telecommunication systems use the infrastructure of, for example, an existing computer network, making a parallel, second infrastructure for telephony superfluous. IP telephones can directly be connected to such a telecommunication system, whereas the use of conventional telephones requires the utilization of a so-called media gateway, which translates line-switched data into packet-switched data and vice versa. In doing so, each media gateway generates an internal clock, which will be needed if, for example, terminals shall be connected to the media gateway via an ISDN interface.
Radio base stations can also be connected to the media gateways in order to operate wireless terminals. To enable a roaming or handover between radio base stations, the radio base stations must be operated in a clock-synchronous way. If the so-called jitter becomes to large, i.e. if the difference with which several radio base stations start emitting the same data frame, fluctuates beyond a certain value, the terminal synchronized onto one radio base station will not recognize the other radio base station and a roaming or handover will not be possible. Therefore, the media gateways to which the radio base stations are connected have to be synchronized, which is, however, not possible with the necessary precision through a packet-switching network.